Redis序列化对象的时候报错如下

java.lang.ClassCastException: com.ppdai.cbd.ddp.thirdparty.contract.bhxtzx.BHXTZXTask cannot be cast to java.lang.String        at org.springframework.data.redis.serializer.StringRedisSerializer.serialize(StringRedisSerializer.java:33)        at org.springframework.data.redis.core.AbstractOperations.rawValue(AbstractOperations.java:117)        at org.springframework.data.redis.core.DefaultListOperations.leftPush(DefaultListOperations.java:71)        at org.springframework.data.redis.core.DefaultBoundListOperations.leftPush(DefaultBoundListOperations.java:60)        at com.ppdai.realtime.datachannel.pullservice.entity.RedisQueue.pushFromHead(RedisQueue.java:63)        at com.ppdai.realtime.datachannel.pullservice.redisconfig.RedisTaskSender.sendTask(RedisTaskSender.java:35)        at com.ppdai.realtime.datachannel.pullservice.redisconfig.RedisTaskSender$sendTask.call(Unknown Source)        at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:125)

BHXTZXTask是自己定义的Bean，因此问题就变成了自定义的对象不能转成String对象，为什么会需要转成String对象呢

因为redis默认使用jdkSerializer，看RedisTemplate的代码如下，

afterPropertiesSet函数

public class RedisTemplate
     
       extends RedisAccessor implements RedisOperations
      
       , BeanClassLoaderAware {    public void afterPropertiesSet() {        super.afterPropertiesSet();        boolean defaultUsed = false;        if (defaultSerializer == null) {            defaultSerializer = new JdkSerializationRedisSerializer(                    classLoader != null ? classLoader : this.getClass().getClassLoader());        }        if (enableDefaultSerializer) {            if (keySerializer == null) {                keySerializer = defaultSerializer;                defaultUsed = true;            }            if (valueSerializer == null) {                valueSerializer = defaultSerializer;                defaultUsed = true;            }            if (hashKeySerializer == null) {                hashKeySerializer = defaultSerializer;                defaultUsed = true;            }            if (hashValueSerializer == null) {                hashValueSerializer = defaultSerializer;                defaultUsed = true;            }        }        if (enableDefaultSerializer && defaultUsed) {            Assert.notNull(defaultSerializer, "default serializer null and not all serializers initialized");        }        if (scriptExecutor == null) {            this.scriptExecutor = new DefaultScriptExecutor
       
        (this);        }        initialized = true;    }}
       
      
     

 

查看源码，如下，通过rawValue()函数获取序列化之后的字节码

public Long leftPush(K key, V value) {        final byte[] rawKey = rawKey(key);        final byte[] rawValue = rawValue(value);        return execute(new RedisCallback
     
      () {            public Long doInRedis(RedisConnection connection) {                return connection.lPush(rawKey, rawValue);            }        }, true);    }
     

private byte[] rawValue(Object value) {
      if (valueSerializer == null && value instanceof byte[]) {
         return (byte[]) value;    }    return valueSerializer.serialize(value); }

通过 valueSerializer序列化来序列化对象, redis如果不配置，默认 valueSerializer的序列化是会使用

StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();        JdkSerializationRedisSerializer jdkSerializationRedisSerializer = new JdkSerializationRedisSerializer();        System.out.println(redisTemplate.hasKey("bohai_credit"));        redisTemplate.delete("bohai_credit");        System.out.println(stringRedisSerializer.serialize("bohai_credit"));        System.out.println(jdkSerializationRedisSerializer.serialize("bohai_credit"));

[B@21831984[B@4488db1f

运行结果如上所示。